Traditional xeroprinting, for example, as disclosed in Schaffert, ELECTROPHOTOGRAPHY, p. 209, Vol. 2, 1975, usually involves electrostatic creation of a toner image, transfer of the toner image to a conductive support and fusing of the toner image to the support to make a xeroprinting master. The master can be repeatedly charged and toned and the toner image transferred to create a large number of duplicates of the master. See also U.S. Pat. Nos. 4,129,072; 4,273,438; 4,286,031; 4,443,093.
U.S. Pat. Nos. 4,338,386; 4,471,694; and 4,286,031 describe similar processes but suggest cleaning the fixed toner image off the substrate after use so that the substrate can be reused. For example, it can be cleaned off by solvent or by scraping.
Reuse of the substrate is desirable because it permits the use of a permanent master substrate in the form of drums and endless webs in xeroprinting apparatus, eliminating the need for separately forming masters and hand mounting them in the xeroprinting apparatus. However, the use of solvents, scraping and the like to clean a fused image off the substrate is impractical. At the very least, it greatly limits the materials that can be used.
A number of processes suggest methods of obtaining a number of images out of a single exposure without actually fusing a toner image as in the art cited above. See for example, U.S. Pat. Nos. 4,297,422 and 4,298,032 which are representative examples only. Unfortunately, each of these processes have specific problems of their own. For example, U.S. Pat. No. 4,297,422 includes a step of uniform exposure through a transfer substrate which restricts the process to use with at least translucent receiving sheets or some sort of translucent intermediate.